I think you can easly know what I want to do. However, upper method is so ugly. Why? First, it doesn’t work J Second, It will make memory leak. The static class must do not handle any UIElement’s events.

In these case, there are two solutions I found.

First, use WeakEvent. This is greate solution, but there is problem it is hard to implement WeakEvent. See this CodeProject site. – Weak Event in C#